ZEND PHP 5 Certification STUDY GUIDE

6 ” PHP Basics
Comments
Another common part of any programming language is comments. It is a good programming
practice to comment every function, class, method or property in your
code (although you will likely come across lots of code that is poorly commented—or
not at all). Remember—any code that took thought to write will take thought to reread
after several days, months or in some cases, years.
As with tags, PHP gives you multiple choices for your comments:
// Single line comment
i
# Single line comment
/* Multi-line
comment
*/
/**
* API Documentation Example
*
* @param string $bar
*/
function foo($bar) { }
Both types of single line comments, // and #, can be ended using a newline (\r, \n or
\r\n) or by ending the current PHP block using the PHP closing tag—?>.
Because the closing tag ?> will end a comment, code like // Do not show this ?> or
this will output or this, which is not the intended behaviour.
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
Whitespace
Finally, we reach a subject with very little substance (pun definitely intended):
whitespace. PHP is whitespace-insensitive, except in a few key areas. This means
that there are no requirements to use (or not to use) a specific type of whitespace
character (e.g.: tabs rather than spaces), or a particular number of whitespace characters.
However, there are a few limitations: